The original concept of this invention arose from difficulties encountered by one of the inventors in hospital delivery rooms where the structure and associated apparatus of existing obstetric vacuum extractors for assisting childbirth proved to be cumbersome.
Modern technology has advanced considerably in providing apparatus to monitor the progress of mothers in labor and the condition of the fetus during labor. The process of vaginal birth may be assisted by hard steel forceps or a variety of available vacuum extraction devices. Although forceps are highly effective when used in the proper circumstances, vacuum extraction devices are less likely to cause maternal or infant injury and can replace forceps in many cases.
Existing vacuum extractor devices include a variety of obstetric vacuum cups on the end of a handle combined with a hose attached to an external vacuum source. The procedure for using the vacuum extractor is to draw a vacuum on the cup only during uterine contractions. The vacuum cup is intended to hold on to the baby's head and to assist the birth by allowing the physician to pull on the baby's head as the mother pushes. Upon the cessation of each contraction, the vacuum is released until the next contraction begins. The reasons for this procedure are well known in the field and need not be discussed here.
The main problem with existing apparatus is the need for control of an external vacuum source. This requires either the physician's free hand or a second person with coordinated action between the physician and this second person. Additionally, the speed of response in drawing the vacuum is directly proportional to the volume and diameter of the hoses and ducts intermediate the vacuum cup and the vacuum pump. The greater the length of the tubes and the larger the diameter involved, the longer it will take to evacuate the system and produce the vacuum needed to secure the cup to the baby's head.
It must be possible to repeatedly and quickly regenerate the vacuum for these reasons:
1) Air leakage between the cup and the baby's head is common, reducing the hold of the cup on the baby's head. This leakage is due to the baby's hair, wires used for electronic fetal heartbeat monitoring, and partial cup disengagement.
2) Fluids such as amniotic fluid, blood and vernix commonly enter the cup and occupy some space.
3) The vacuum is purposely interrupted between uterine contractions and must be regenerated to enable the physician to pull and assist the birth.